相关试题
【单选题】
测量电流时,万用表的接线方法与直流电流表一样，应把万用表___在电路中。测量直流电压时，应把万用表与被测电路并联。
【单选题】
串联电路中各电阻两端电压的关系是___。
A. 各电阻两端电压相等
B. 阻值越小两端电压越高
C. 阻值越大两端电压越高
【单选题】
确定正弦量的三要素为 ___。
A. 相位、初相位、相位差
B. 最大值、频率、初相角
C. 周期、频率、角频率
【单选题】
当电压为5V时,导体的电阻值为5欧,那么当电阻两端电压为2V时,电阻值为___欧。
【单选题】
对称负载接成星形时,三相总电流___。
A. 等于零
B. 等于其中一相电流的三倍
C. 等于其中一相电流。
【单选题】
一段有源支路如图1所示，AB两端的电压UAB为___。
A. 10 V
B. —2V
C. 2V
D. —10V
【单选题】
如图2电路中，等效电阻=___
A. 150Ω
B. 900Ω
C. 600Ω
D. 100Ω
【单选题】
电流表的读数是4A，则电路中电流表的读数是 ___
【单选题】
在R、L、C串联电路中，已知＝3Ω，＝5Ω，＝8Ω，则电路的性质为 ___。
A. 感性
B. 容性
C. 阻性
D. 不能确定
【单选题】
工业生产中大量的设备均为感性负载，功率因数往往很低，常采取___的方法来提高电网的功率因数。
A. 并联电容
B. 串联电容
C. 串联电感
D. 并联电感
【单选题】
交流电压表及电流表指示的数值是___
A. 平均值
B. 有效值
C. 最大值
D. 瞬时值
【单选题】
RLC串联电路发生谐振，，R=10Ω，Ω，则谐振时的感抗为___
A. 10Ω
B. 40Ω
C. 20Ω
D. 30Ω
【单选题】
RL从电路获得最大功率，此时RL=___。
【单选题】
使用电解电容时___。
A. 负极接高电位，正极接低电位
B. 正极接高电位，负极接低电位
C. 正极接高电位，负极也可以接高电位
D. 不分正负极
【单选题】
开关接1时，电压表的读数为___。
A. 0V
B. 0.2V
C. 1.96V
D. 2V
【单选题】
开关接2时，电流表的电流为___。
A. 0A
B. 10A
C. 0.2A
D. 约等于0.2A
【单选题】
开关接1时，电流表中流过的短路电流为___。
A. 0A
B. 0.2A
C. 10A
D. 约等于0.2A
【单选题】
正弦交流电常用的表达方法有___。
A. 解析式表示法
B. 波形图表示法
C. 相量表示法
D. 以上都是
【单选题】
电感两端的电压相位超前电流___。
A. 90°
B. 180°
C. 360°
D. 30°
【单选题】
电容两端的电压相位滞后电流___。
A. 30°
B. 90°
C. 180°
D. 360°
【单选题】
应用戴维南定理求含源二端网络的输入等效电阻是将网络内各电动势___
【单选题】
LC 选频振荡电路，当电路频率等于谐振频率时，电路性质为___。
A. 电阻性
B. 感性
C. 容性
D. 纯电容性
【单选题】
阻值为4Ω的电阻和容抗为3Ω的电容串联，总复数阻抗为___
A. 3+j4
B. 3-j4
C. 4+j3
D. 4-j3
【单选题】
电动势为10V，内阻为2Ω的电压源变换成电流源时，电流源的电流和内阻是___
A. 10A，2Ω
B. 20A，2Ω
C. 5A，2Ω
D. 2A，5Ω
【单选题】
电流为5A，内阻为2Ω的电流源变换成一个电压源时，电压源的电动势和内阻为___
A. 10V，2Ω
B. 2.5V，2Ω
C. 0.4V，2Ω
D. 4V，2Ω
【单选题】
额定电压都为220V的40W、60W、100W三灯泡串联在220V的电源中，它们的发热量由大到小排列为___
A. 100W 60W 40W
B. 40W 60W 100W
C. 100W 40W 60W
D. 60W 100W 40W
【单选题】
在正弦交流电的解析式i=ImSin(ωt +φ)中，φ表示___
A. 频率
B. 相位
C. 初相位
D. 相位差
【单选题】
正弦交流电压u=100Sin(628t + 600)V，它的最大值为___。
A. 100 V
B. 100 V
C. 60V
D. 628 V
【单选题】
能表示容性电路电压与电流关系的相量图是___。
【单选题】
电路中___定律指出：流入任意一节点的电流必定等于流出该节点的电流。
A. 欧姆
B. 基尔霍夫电流
C. 楞次
D. 基尔霍夫电压
【单选题】
已知电源电压为12 V ,四只相同灯泡的工作电压都是6 V，要使灯泡都能正常工作，则灯泡应___
A. 全部串联
B. 两只并联后与另两只串联
C. 两两串联后再并联
D. 全部并联
【单选题】
用戴维南定理分析电路“入端电阻”时，应将内部的电流源___处理。
【单选题】
任何一个含源二端网络都可以用一个适当的理想电压源与一电阻___来代替。
A. 串联
B. 并联
C. 串联或并联
D. 随意联接
【单选题】
用交流电流表测得交流电流10A，则电路中电流的最大值为___。
A. 10A
B. 14.1A
C. 20A
D. 70.7A
【单选题】
如右图所示电路中，已知各支路的电流I1=I2=10A， 则电路的总电流I为___。
A. 20A
B. 0 A
C. 14.1A
D. 50A
【单选题】
1杂质半导体中多数载流子的浓度取决于___
【单选题】
2在电场作用下，空穴与自由电子运动形成的电流方向___
推荐试题
【单选题】
It wasn’t such a good dinner ___ she had promised us.
A. that
B. which
C. as
D. what
【单选题】
The road now ___two kilometers beyond the river.
A. develops
B. extends
C. expands
D. widens
【单选题】
It was claimed that the level of alcohol in the man’s blood was ___ to cause an accident.
A. sufficient
B. adequate
C. enough
D. accurate
【单选题】
Medical care reform has become this country’s most important public health ___.
A. question
B. stuff
C. matter
D. problem
【单选题】
His retail business in the city___ rapidly between the wars.
A. enlarged
B. extended
C. widened
D. expanded
【单选题】
Many frogs ___ the sound of their voice using special sacs(囊) in their throat.
A. amplify
B. widen
C. expand
D. enlarge
【单选题】
Some old people don’t like pop songs because they cannot ___ so much noise.
A. resist
B. sustain
C. tolerate
D. undergo
【单选题】
I have kept that portrait where I can see it every day, as it always ___ me of my university days in London.
A. recollects
B. reminds
C. recalls
D. invokes
【单选题】
The article suggests that when a person is under unusual ___ he should be especially careful to have a well-balanced diet.
A. weight
B. stress
C. press
D. nerve
【单选题】
You should hire a more ___ manager than the one you currently have.
A. sufficient
B. effective
C. respective
D. efficient
【单选题】
Surgeons began to ___ their hands and arms with soap and water before operating.
A. scrub
B. enhance
C. rub
D. exhibit
【单选题】
He might let something ___ in a moment of weakness.
A. slip
B. leak
C. to slip
D. to leak
【单选题】
Do not ___ the salad until you are ready to serve.
A. mix
B. toss
C. fling
D. eat
【单选题】
The ___ for which he had fought all his life no longer seemed important to him.
A. aims
B. objectives
C. subjects
D. goals
【单选题】
You should pause and ___ now.
A. tweet
B. ponder
C. squander
D. gossip
【单选题】
Eating too much fat can ____heart disease and cause high blood pressure.
A. contribute to
B. attribute to
C. attest to
D. devote to
【单选题】
It soon ___ that what she loved was not my person but my wealth.
A. widened
B. expanded
C. extended
D. developed
【单选题】
I want to buy a new tie to ___ this brown suit.
A. go into
B. go after
C. go with
D. go through
【单选题】
Our company decided to ___ the contract because a number of the conditions in it had not been met.
A. destroy
B. resist
C. assume
D. cancel
【单选题】
My first ___ was to turn and run.
A. institute
B. institution
C. instinct
D. tuition
【单选题】
I think it’s time I ___ in a new computer.
A. invested
B. insulted
C. interacted
D. impacted
【单选题】
The jeweler will ____ the inside of the ring with her name.
A. carve
B. engrave
C. cut
D. engross
【单选题】
He was bleeding from a _____ on his forehead.
A. lash
B. gash
C. ash
D. sash
【单选题】
Let us go to the next ______ on the agenda.
A. matter
B. debate
C. speech
D. item
【单选题】
They are _____ moving their office outside London.
A. considered
B. discussing
C. pondering
D. negotiating
【单选题】
Although she _____ the old pot thoroughly, she could not make it look completely clean.
A. scrubbed
B. washed
C. made
D. screwed
【单选题】
The mistake will remain an indelible ____ on his memory.
A. stain
B. thing
C. issue
D. accident
【单选题】
The wheel ____ through my frozen hand, and the car went right across the road.
A. slipped
B. sipped
C. dashed
D. disappeared
【单选题】
The cupboard was ____ with old fishing tackle.
A. stuffed
B. stocked
C. stored
D. filled
【单选题】
The decision depended on the ____ of a coin.
A. loss
B. lot
C. toss
D. sign
【单选题】
Teaching can be a tiring and ____ job.
A. meaningless
B. stressed
C. rewarded
D. stressful
【单选题】
The building is partly a museum and partly a private ____.
A. place
B. area
C. community
D. residence
【单选题】
Stop ______ your foot.
A. tossing
B. wiggling
C. exhibiting
D. reviewing
【单选题】
It was a bloody ___ between the two armies.
A. rebellion
B. encounter
C. meet
D. fight
【单选题】
They conferred on the best way to ______ business.
A. extend
B. adjust
C. expand
D. adopt
【单选题】
We had a party last month, and it was a lot of fun, so let’s have ____ one this month.
A. another
B. the other B. more D. other
【单选题】
I decided to go to the library as soon as I ____.
A. finish what I did
B. finished what I did
C. would finish what I was doing
D. finished what I was doing
【单选题】
The speaker, ______ for her splendid speeches, was warmly received by the audience.
A. having known
B. being known
C. knowing
D. known
【单选题】
No sooner had we reached the top of the hill ______ we all sat down to rest.
A. when
B. then
C. than
D. until
【单选题】
___ energy under the earth must be released in one form or another, for example, an earthquake.
A. Accumulated
B. Gathered
C. Assembled
D. Collected
